A variety of silicon containing precursor have been used to deposit Si-containing thin films on various substrates by vapor deposition processes. The choice of the suitable silicon precursor and, when applicable, of the co-reactant are generally driven by the target film composition and properties, as well as by the constraints brought by the substrate on which the film is to be deposited. Some substrates may require low temperature deposition processes. For instance, deposition on plastic substrates or Si substrates coated with organic films may require deposition temperatures below 100° C. (i.e., 20° C.-100° C.), while maintaining a reasonable deposition rate to be of industrial interest. Such films may be used as spacer-defined lithography application in semiconductor fabrication, but also for sealing organic light-emitting diode (OLED) devices or creating moisture diffusion barriers on films. Similar constraints at different temperature ranges appear in the different steps of semiconductor manufacturing, such as, capping layers over metals, gate spacers, etc.
Trisilylamine (TSA) is a molecule with a high Si content and has the formula of N(SiH3)3. TSA may be used as a low temperature (T) silicon nitride precursor (see, e.g., U.S. Pat. No. 7,192,626), as well as a precursor for flowable CVD (see, e.g., U.S. Pat. No. 8,846,536, US 2014/0057458 or U.S. Pat. No. 8,318,584). However, while TSA appears as a versatile precursor (Carbon-free and low T capability) for a variety of thin film deposition processes, it's applicability to thermal ALD has been limited (see, e.g., U.S. Pat. No. 8,173,554, indicating that plasma activation is necessary to obtain a meaningful growth per cycle).
US2014/0363985 A1 discloses amino-silylamines used for forming a silicon-containing thin-film having a generic formula of R1R2R3Si—N(SiR4R5—NR6R7)2, wherein R1 to R5 are each independently hydrogen, halogen, (C1-C7)alkyl, (C2-C7)alkenyl, (C2-C7)alkynyl, (C3-C7)cycloalkyl or (C6-C12)aryl. US2014/0158580A describes an alkoxysilylamine having a TSA-like structure. U.S. Pat. No. 7,122,222 uses a Si—C bond free hydrazinosilane precursor [R12N—NH]nSi(R2)4-n] to depist SiN, SiO2 and SiON films. Silazane compounds N—(SiR1R2R3)mR43-m disclosed in WO2013/058061 are used as a coating gas. (RR1R2Ma)yA(R3)x disclosed in U.S. Pat. No. 5,332,853 is used as a catalytic compound to produce a functionalized alkylalkali metal compound. Similar patents include U.S. Pat. No. 5,663,398A, U.S. Pat. No. 5,332,853A, U.S. Pat. No. 5,340,507A, EP 525881 A1, etc.
As such, industries using vapor-based deposition processes such as CVD or ALD (in all possible meanings, such as LPCVD, SACVD, PECVD, PEALD, etc.) are still looking for precursors that are ideal for their applications, i.e. having the highest possible deposition rates within the constraints of their processes, substrates and film targets.